Zinc SmeltingWhat role did it play in the
Donora disaster?
Zinc Ore
Main ComponentZinc sulfate (ZnS) is the main
component of zinc ore
The Zinc Smelting Process
Two Smelting ProcessesHydrometallurgic & Pyrometallurgic
Contrast the two zinc refining processes (2 differences)
Which process would be used to smelt zinc ore with lots of lead?
Which process is the most used globally?
Step 1: Roasting__ ZnS + __ O2 __ ZnO + __ S CaF2 + H2SO4 → CaSO4 + 2 HF What type of reaction is this? (See the choices above)
Step 1: Roasting ByproductsWhere does the sulphur go?
Sulphur combines with oxygen forming sulphur dioxide which is then converted sulfur trioxide and finally to sulphuric acid.
S + O2 > SO2
2 SO2 + O2 > 2 SO3
H2O + SO3 > H2SO4
Type of reaction:
Step 1: Roasting ByproductsImportant note: During this step, other “waste” compounds are broken down releasing various harmful gases.
Example: Fluorspar (CaF2) reacts with sulphuric acid forming calcium sulfate and hydrogen fluoride gas.
CaF2 + H2SO4 > CaSO4 + 2 HF
Type of reaction:
Hydrometallurgic Process
Step 2: LeachingSulphuric acid is added to dissolve zinc oxide forming zinc sulphate and water.
Write the chemical equation for this reaction. Prove that it is balanced.
Activity of MetalsCircle the MORE reactive element in each pair.
Pair 1: Pb Li
Pair 2: Ca Ni
Pair 3: Mg Mn
Li
Most Reactive
Least Reactive
RbK
BaSrCaNaMgAl
MnZnCrFeCdCoNiSnPbH2
SbBiCuHgAgPt
Au
Step 3: PurificationPowdered zinc (Zn) is added to the zinc sulphate solution. The zinc (Zn) reacts with copper sulphate (CuSO4) – one of the impurities. Predict how zinc will react based on the activity chart. Write the correct equation here. Identify the type of reaction:
Li
Most Reactive
Least Reactive
RbK
BaSrCaNaMgAl
MnZnCrFeCdCoNiSnPbH2
SbBiCuHgAgPt
Au
Step 4: Electrolysis
Circle the zinc product.2 ZnSO4 + 2 H2O > 2 H2SO4 + 2 Zn + O2
Pyrometallurgic Process
Step 2: SinteringThe zinc oxide is sintered where carbon in combustion gases reacts with impurities such as lead oxide, cadmium oxide and fluorine…
CO2 + PbO > PbCO3
CO2 + CdO > CdCO3
CO2 + 4F > CF4 + O2
Step 3: RetortingBalance this equation. __ C + __ O2 > __ CO
Fill in the missing compounds. ZnO + ____ > Zn (vapor) + ____